1. Field of the Invention
The present invention is directed to telephone sets in general, and in particular to electronic subscriber sets for both residential and business use. More particularly still, it is directed to a flexible, user responsive, micro-processor controlled telephone set with generic directory list memory accessed by the user via dialpad and softkeys, without the complication of a computer keyboard.
2. Prior Art of the Invention
With the proliferation of call-waiting (CW) and calling-number identification (CNID) service, subscriber telephone sets have acquired modem, data processing and display capability. Indeed, Motorola provides since 1992 a caller ID integrated circuit with on-chip ring detection under the description MC145447 for use in telephones.
Furthermore, modem cental offices (CO) are capable of providing enhanced services, such as in U.S. Pat. No. 4,661,975 granted Apr. 28, 1987 to S. M. Brecher for Enhanced Call-Waiting Service. The patent discloses a process for controlling a telephone switching system which gives a telephone customer alternative ways of handling an incoming call while that customer is engaged with an existing call. The conventional call-waiting process is modified by permitting the dual tone multifrequency buttons to be operated for a predetermined short interval after the call-waiting signal is given to the called customer responsive to the particular tone signals keyed. The switching system is enabled to send a busy tone or a predetermined announcement to the calling party or to reroute the calling party to an alternate destination.
U.S. Pat. No. 4,879,743 granted Nov. 7, 1989 to E. T. Burke et al, on the other hand, discloses a sophisticated PBX system for use with adjuncts such as a programmable voice message system, and passes data messages to the adjunct via DTMF tones.
U.S. Pat. No. 4,924,496 granted May 8, 1990 to R. Figa et al discloses an automatic incoming telephone call number display system for detecting an incoming call and identifying the party associated with the incoming call number. The system includes a directory of telephone numbers and parties associated with those numbers. Circuitry detects the origin telephone number of an incoming telephone call and compares that number with numbers in the directory for identifying the calling party. A display permits the user to view the incoming call number and party associated with that number. The incoming telephone call number display system disclosed includes a liquid crystal display, an alpha keypad and a numeric keypad.
The above mentioned United States patents are incorporated herein by reference.